Breast compression in the mammographic field is necessary to provide images of improved quality since the breast is an object of wide geometric change. For example, compression has reduced the thickness variation of the breast from the nipple to the chest wall. An image of the compressed breast therefore will provide more uniform information in the developed image. Breast compression also inhibits the movement of the breast during exposure thereby reducing image degradation due to breast movement.
Prior art x-ray systems, such as that shown in U.S. Pat. No. 3,824,397, generally incorporate integral compression devices. The degree of flexibility in positioning the integral device to accommodate the desired image view or breast size is limited by the associated x-ray system. Further, the non-universality of integral compression devices limit their capability of incorporating significant improvements in breast compression devices and techniques. An independent compression device will serve those users having an existing x-ray facility who are unwilling to dedicate a portion of the equipment to mammography.
The breast compression device, in addition to being independent of the x-ray system, should preferably be lightweight and portable and incorporate a compression member which may be adjusted in a plurality of directions, allows breast visualization during compression and provides for optiminum compression over the contacted breast area.